1. Field of the Invention
The present invention relates to dryers, and more particularly, to a sensor assembly for determining dryness of a load of wet clothes being dried in an automatic dryer.
2. Background of the Related Art
The automatic dryer dries a wet state drying object (for an example, clothes and the like) having washing thereof completed, automatically. In general, the dryers, having a system for supplying hot air heated by a heater to a drum for drying, are sorted as exhaust type dryers and condensing type dryers.
The exhaust type dryer dries the drying object by discharging air having carried out the drying to have a low temperature and to become humid to an exterior, drawing fresh airs heating the air, and supplying the heated air to the drum.
The condensing type dryer dries the drying object by condensing the air having carried out the drying to have a low temperature and to become humid, for removing moisture therefrom, heating, and supplying to the drum again.
In general, both the exhaust, and condensing type dryers employ an operating method in which a heater and a blower are operated for a preset time period for drying the drying object in the drum. However, the dryers having employed the method have the following problems.
The drying of different kinds of drying objects having different materials, weights, volumes, moisture contents, and the like by the same operating method for the preset time period causes to fail to provide an optimal drying performance, always. That is, there can be an occasion when drying of some of the drying objects is not finished even if operation of the dryer is finished, when re-operation of the dryer is required.
The failure in constant provision of the optimal drying performance leads the dryer set to operate for a longer time period, to require a much drying time period and a long time operation of the heater, and blower motor more than required, to result in waste of energy.
Taking the foregoing problems into account, introduction of a feed back system is required, in which the dryer is operated after dryness or humidity of laundry is sensed and provided to a controller during drying, an optimal operation condition is calculated based on information obtained by sensing, and setting of a heating quantity of the heater, a blowing rate of the blower, a rotation speed of the drum, an operation time period, and the like are changed.
In order to introduce the foregoing feed back system, a sensor is required for sensing dryness or humidity of the laundry. However, since the drum keeps rotating during operation, it is required to fit the sensor such that a stable exchange of electrical signals between the sensor and the controller is possible. Consequently, for the introduction of the feed back system, a solution for a sensor fitting structure is also required, as well.